Resin beads and use in processing of aqueous solutions

ABSTRACT

Provided is a resin bead comprising functional groups of structure (S1).

TECHNICAL FIELD

A common industrial goal is the processing of aqueous solutions. Acategory of aqueous solutions of interest are aqueous solutions thatcontain one or more sugar and/or one or more sugar alcohol. It isdesirable to process such an aqueous solution in a way that separatessome or all of the sugars and/or sugar alcohols from each other. It isalso desirable to process such an aqueous solution in a way that iscapable of separating some or all of the sugars and/or sugar alcoholsfrom other compounds that may be present in the aqueous solution. It isalso desirable to be able to process aqueous solutions having pH below6.

BACKGROUND ART

In the past, aqueous solutions of sugars have been processed to separatethe sugars by using resin beads that have sulfonic acid groups incalcium form. It has been found that, in order to effectively separatethe sugars, such resin beads needed to be present in a collection ofresin beads that had both a relatively small mean diameter and arelatively small uniformity coefficient. Production of such uniformcollections of small resin beads is difficult and expensive. It isdesired to provide resin beads that are capable separating sugars, evenwhen the collection of resin beads has relatively large mean diameterand relatively large uniformity coefficient.

J. A. Vente, et al., in “Sorption and Separation of Sugars withAdsorbents Based on Reversible Chemical Interaction,” Adsorption Scienceand Technology, vol. 24, p. 171, 2006, describe a boronicacid-functionalized poly(acrylamide) resin, used at pH 6 or pH 9, thatis used to separate glucose and fructose. It is desired to provide resinbeads of a different composition that are capable of separating avariety of sugars and sugar alcohols. It is also desired to provideresin beads that are capable of processing aqueous solutions at pH lessthan 6.

DISCLOSURE OF INVENTION

The following is a statement of the invention.

A first aspect of the present invention is a resin bead comprisingfunctional groups of structure (S1)

wherein —X— is a bivalent linking group, wherein —Y is a monovalentgroup having structure (S2)

wherein the circular structure in structure (S2) has four or more atoms,

wherein the mole ratio of multivalent atomic cations to —X— groups iseither 0:1 or is 0.01:1 or lower.

A second aspect of the present invention is a method of processing anaqueous solution, wherein the aqueous solution comprises one or moredissolved sugar, one or more dissolved sugar alcohol, or a mixturethereof, wherein the method comprises bringing the aqueous solution intocontact with a collection of resin beads, wherein the resin beadscomprise functional groups of structure (S1)

wherein —X— is a bivalent linking group, wherein —Y is a monovalentgroup having structure (S2)

wherein the circular structure in structure (S2) has four or more atoms.

The following is a detailed description of the invention.

As used herein, the following terms have the designated definitions,unless the context clearly indicates otherwise.

A “polymer,” as used herein, is a relatively large molecule made up ofthe reaction products of smaller chemical repeat units. As used herein,the term “resin” is a synonym for “polymer.” Polymers may havestructures that are linear, branched, star shaped, looped,hyperbranched, crosslinked, or a combination thereof; polymers may havea single type of repeat unit (“homopolymers”) or they may have more thanone type of repeat unit (“copolymers”). Copolymers may have the varioustypes of repeat units arranged randomly, in sequence, in blocks, inother arrangements, or in any mixture or combination thereof.

Vinyl monomers have the structure

where each of R¹, R², R³, and R⁴ is, independently, a hydrogen, ahalogen, an aliphatic group (such as, for example, an alkyl group), asubstituted aliphatic group, an aryl group, a substituted aryl group,another substituted or unsubstituted organic group, or any combinationthereof. Vinyl monomers are capable of free radical polymerization toform polymers. A vinyl polymer is the product of polymerizing the doublebonds of a collection of vinyl monomers.

Styrenic monomers are vinyl monomers in which each of R¹, R², and R³ ishydrogen and —R⁴ has the structure

where each of R¹⁵, R¹⁶, R¹⁷, R⁸, and R¹⁹ is, independently, a hydrogen,a halogen, an aliphatic group (such as, for example, an alkyl group or avinyl group), a substituted aliphatic group, an aryl group, asubstituted aryl group, another substituted or unsubstituted organicgroup, or any combination thereof.

Acrylic monomers are vinyl monomers in which each of —R¹ and —R² ishydrogen; —R³ is either hydrogen or methyl; and —R⁴ has one of thefollowing structures:

where each of R¹¹, R¹², and R¹⁴ is, independently, hydrogen, a C₁ to C₁₄alkyl group, or a substituted C₁ to C₁₄ alkyl group.

A reaction among monomers to form one or more polymers is referred toherein as a polymerization process. The residue of a monomer as part ofa polymer after a poly-merization process has taken place is knownherein as a polymerized unit of that monomer.

As used herein, a polymer has a “backbone.” To identify the backbone, apathway is identified by starting at one end of the polymer andproceeding from one atom to the next, proceeding along covalent bonds,without any doubling back along the pathway, until another end of thepolymer is reached. As used herein, an “end” of a polymer is a site ofchain termination of the polymerization reaction that formed thepolymer. If the polymer is branched or crosslinked, multiple suchpathways are identified, connecting every end point of the polymer toevery other end point of the polymer. Any atom lying upon one or more ofthese pathways is part of the polymer backbone. Individual atoms thatare not part of any such pathway and chemical groups in which none ofthe atoms are part of any such pathway are known herein as “pendant.”.Some examples are as follows. In linear polyethylene, all the carbonatoms are in the backbone. In a linear polyamide formed bypolymerization of c) aminoundecanoic acid, all the carbon and nitrogenatoms are in the backbone. In a vinyl polymer, each polymerized unit isa residue of a monomer of structure (Ml). The carbon atoms shown instructure (Ml) form the backbone of the vinyl polymer, while —R¹, —R²,—R³, and —R⁴ are pendant. In linear polystyrenehomopolymer, the carbonatoms from the vinyl groups of the styrene monomers form the backbone,while the aromatic rings are pendant.

In chemical structures shown herein, when a chemical group (i.e., astructure of bonded atoms that is not a complete molecule) is depicted,the point of attachment of the group to other atoms is shown herein bythe symbol

For example a hydroxyl group would be depicted herein as

and a methyl group would be depicted herein as

If the hydroxyl group and the methyl group were joined, the result wouldbe methanol, depicted as HO—CH₃ or as HOCH₃, or as CH₃OH.

Resin beads are individual particles, each containing 50% or more byweight of polymer. Beads are in the solid state at 23° C. If a particleis not spherical, the diameter of the particle is taken herein to be thediameter of an imaginary sphere that has the same volume as theparticle.

A collection of resin beads may be characterized by the particlediameters. The collection may be characterized by the harmonic meandiameter or by the volume-average diameter. The parameter D60 of acollection of resin beads is a diameter such that exactly 60% by volumeof the beads in the collection have diameter D60 or less. The parameterD10 of a collection of resin beads is a diameter such that exactly 10%by volume of the beads in the collection have diameter D10 or less. Theuniformity co-efficient (UC) is the quotient UC=D60/D10. A lower UCmeans that the distribution of diameters is more nearly uniform (i.e.,the beads are more nearly all the same diameter).

Resin beads may be characterized by their porosity. The size of thepores in a resin bead are measured by the Brunauer-Emmett-Teller (BET)method using nitrogen gas. Resin beads are said herein to be“macroporous” if the median pore diameter is 20 nm or greater. Resinbeads having median pore diameter less than 20 nm, including those whosepores are too small to be detected reliably by the BET method, are saidherein to be “gel” resin beads.

As used herein, a chemical group is said herein to be “substituted” if asubstituent (that is, an atom or chemical group) is attached. Suitablesubstituents include, for example, alkyl groups, alkynyl groups, arylgroups, halogen atoms, nitrogen containing groups including aminegroups, oxygen-containing groups including carboxyl groups,sulfur-containing groups including sulfonic acid groups, nitrile groups,and combinations thereof.

As used herein, an aqueous solution is a composition that is liquid at23° C. and that contains one or more solute compound dissolved in anaqueous solvent. A solvent is aqueous if it is liquid at roomtemperature and contains 50% or more water, by weight based on theweight of the solvent. A dissolved compound is considered “solid” ifthat compound, in the pure state, either (i) is liquid at 23° C. and hasboiling point of 110° C. or higher or else (2) is solid at 23° C.

As used herein, a compound is “organic” if it contains one or morecarbon atoms but does not belong to any of the following classes ofcompounds: binary compounds of carbon, such as carbon oxides, carbonsulfides, carbon disulfide, and similar compounds; ternary compoundssuch as metallic cyanides, metallic carbonyls, phosgene, carbonylsulfide, and similar compounds; and metallic carbonates andbi-carbonates, such as calcium carbonate, sodium carbonate, sodiumbicarbonate, and similar compounds. A compound is “inorganic” if it isnot organic.

As used herein, a monosaccharide is an aldehyde or ketone having 2 ormore hydroxyl groups. A disaccharide is a compound that could be formedby joining two monosaccharides. An oligosaccharide is a compound thatcould be formed by joining three to five monosaccharides. A sugar is amonosaccharide, a disaccharide, or an oligosaccharide. A sugar alcoholis a compound in which all the atoms are selected from carbon, hydrogen,and oxygen; each oxygen atom is present either as part of a hydroxylgroup or as part of an ether linkage between two carbon atoms; all thebonds are single covalent bonds; there are three or more carbon atoms;and there are two or more hydroxyl groups.

An atomic cation is an atom from which one or more electron has beenremoved. A multivalent atomic cation is an atomic cation that has apositive charge of 2 or more.

Ratios are characterized herein as follows. For example, when a ratio issaid to be 3:1 or greater, that ratio may be 3:1 or 5:1 or 100:1 but maynot be 2:1. To state this in a general way, when a ratio is said hereinto be X:1 or greater, it is meant that the ratio is Y:1, where Y isgreater than or equal to X. Similarly, for example, when a ratio is saidto be 15:1 or less, that ratio may be 15:1 or 10:1 or 0.1:1 but may notbe 20:1. To state this in a general way, when a ratio is said herein tobe W:1 or less, it is meant that the ratio is Z:1, where Z is less thanor equal to W.

The first aspect of the present invention is resin beads that have thestructure (S1)

where —X— is a bivalent linking group, wherein —Y is a monovalent grouphaving structure (S2)

where the circular structure in structure (S2) has four or more atoms.

In structure (S2), the group —X— is preferably bonded to a carbon atomthat is part of the backbone of a polymer within the resin bead.Preferably, —X— has the structure (S10)

where G is a chemical group and n is 1 or more. Preferably, n is 2 ormore; more preferably 4 or more; more preferably 6 or more. Preferably nis 14 or fewer; more preferably 12 or fewer; more preferably 10 orfewer; more preferably 8 or fewer. Structure (S10) shows that one ormore -G- groups are connected in a line. When n is greater than 1, allof the -G- groups may be the same as each other, or some of the -G-groups may be different from each other while some of the -G- groups arethe same as each other, or there may be n different -G- groups.Preferred -G- groups are selected from (S11), (S12), (S13), and (S14):

Each of —R⁴, —R⁵, and —R⁶ is, independently of each other, hydrogen,hydroxyl, amino, N-substituted amino, unsubstituted alkyl, orsubstituted alkyl. Each of —R⁷, —R⁸, —R⁹, —R¹⁰, or —R¹¹ is,independently of each other, hydrogen, hydroxyl, amino, N-substitutedamino, unsubstituted alkyl, or substituted alkyl, with the proviso thatone of —R⁷, —R⁸, —R⁹, —R¹⁰, or —R¹¹ is the connection bond between (S14)and an adjacent group or the resin backbone.

Any chemical group that has structure (S10) as defined herein above andthat is bonded to the backbone of the polymer is considered herein to bean —X— group, whether or not it is bonded to a —Y group.

Preferably, —R⁴ is unsubstituted alkyl. Preferably, —R⁴ has 1 to 8carbon atoms; more preferably 1 to 4 carbon atoms; more preferably 1 or2 carbon atoms; more preferably 1 carbon atom. If more than one (S12) ispresent, the plural —R⁴ groups may be chosen independently of eachother. Preferably, —R⁵ is hydrogen, hydroxyl, or unsubstituted alkyl;more preferably hydroxyl. Preferably, —R⁶ is hydrogen, hydroxyl, orunsubstituted alkyl; more preferably hydrogen or hydroxyl. If more thanone (S13) is present, the plural —R⁵ groups may be chosen independentlyof each other. If more than one (S13) is present, the plural —R⁶ groupsmay be chosen independently of each other.

Preferably, one or more of —R⁷, —R⁸, —R⁹, —R¹⁰, and —R¹¹ is hydrogen,hydroxyl, or un-substituted alkyl. More preferably all of —R⁷, —R⁸, —R⁹,—R¹⁰, and —R¹¹, except for the one that is the connection bond to anadjacent group or to the resin backbone, are hydrogen, hydroxyl, orunsubstituted alkyl. More preferably all —R⁷, —R⁸, —R⁹, —R¹⁰, and —R¹¹,except for the one that is the connection bond to an adjacent group orto the resin backbone, are hydrogen.

Preferably, —X— has no (S11) groups. Preferably, the number of (S12)groups in —X— is 3 or fewer; more preferably 2 or fewer; morepreferably 1. Preferably the number of (S13) groups in —X— is 1 or more;more preferably 2 or more; more preferably 3 or more; more preferably 4or more; more preferably 5 or more. Preferably the number of (S13)groups in —X— is 10 or fewer; more preferably 8 or fewer; morepreferably 7 or fewer; more preferably 6 or fewer; more preferably 5 orfewer. Preferably, in —X—, one or more (S13) group is present in which—R⁵ is hydroxyl and —R⁶ is hydrogen. Preferably, in —X—, one or more(S13) group is present in which —R⁵ is hydrogen and —R⁶ is alsohydrogen.

A preferred —X— group has structure (S15)

Preferably, —Y has the structure (S16)

where m is 1 or greater and p is 0 or greater. Each —Z— group and each-J- group is a bivalent chemical group, selected independently of eachother. Preferably, each —Z— group and each -J- group is selected from(S11), (S12), and (S13) as defined above, where, in each —Z— group andeach -J- group, each of —R⁴, —R⁵, and —R⁶ is, independently of eachother, hydrogen, hydroxyl, amino, N-substituted amino, unsubstitutedalkyl, or substituted alkyl.

Preferably, p is 3 or fewer; more preferably 2 or fewer; more preferably1 or fewer; more preferably 0. Preferably, m is 1 or more. Preferably, mis 5 or fewer; more preferably 4 or fewer; more preferably 2 or fewer;more preferably 1.

Preferably, —Y is selected from structures (S3), (S4), and (S5):

where each of -A¹-, -A²-, -A³-, -A⁴-, and -A⁵- is independently selectedfrom structures (S6), (S7), and (S8):

where each of —R¹ and —R² is independently selected from hydrogen,hydroxyl, amine, unsubstituted alkyl, and substituted alkyl, and where—R³ is independently selected from hydrogen, unsubstituted alkyl, andsubstituted alkyl. Preferably one or more of —R¹ and —R² is hydrogen;more preferably both of —R¹ and —R² are hydrogen.

Preferably, one or more of -A¹- and -A²- is (S8); more preferably bothof -A¹- and -A²- are (S8). Preferably, one or more of -A³- and -A⁴- is(S8); more preferably both of -A³- and -A⁴- are (S8). Preferably, -A⁵-is (S8).

Preferably, —Y is (S5).

The resin bead of the present invention may contain one or more “Yreplacement” impurities. When a Y replacement impurity (symbolizedherein as —Y^(R)) is present, the resin bead contains a structure (S17)

where —Y^(R) is an atom, molecule, ion, or chemical group that fallsoutside of the definition of —Y that is given above. The bond between—X— and —Y^(R) may be a covalent bond or an ionic bond or a coordinationbond. Some Y replacement impurities are iron chloride molecules; atomiccations of transition metals; atomic cations of zinc, cadmium, andmercury; and multivalent atomic cations of all types. Preferably, eachtype of Y replacement impurity is either absent or, if present, ispresent in a relatively small amount.

The resin bead of the present invention may contain one or moremultivalent atomic cations. Preferably, multivalent atomic cations areeither absent or are present in a mole ratio of multivalent atomiccations to —X— groups that is 0.01:1 or lower; more preferably 0.001:1or lower. The resin bead of the present invention may contain one ormore atomic cations of any valence value of transition elements.Preferably, atomic cations of transition elements are either absent orare present in a mole ratio of atomic cations of transition elements to—X— groups that is 0.01:1 or lower; more preferably 0.001:1 or lower.

The resin bead of the present invention may contain iron chloride.Preferably, iron chloride is either absent or is present in a mole ratioof iron chloride to —X— groups that is 0.01:1 or lower; more preferably0.001:1 or lower. The resin bead of the present invention may containone or more atomic cations of any valence value of elements selectedfrom zinc, cadmium, mercury, or a mixture thereof. Preferably, atomiccations of elements selected from zinc, cadmium, mercury, or a mixturethereof are either absent or are present in a mole ratio of atomiccations of elements selected from zinc, cadmium, mercury, or a mixturethereof to —X— groups that is 0.01:1 or lower; more preferably 0.001:1or lower.

Preferably, the mole ratio of —Y groups to —X— groups is 0.9:1 orlarger; more preferably 0.95:1 or greater; more preferably 0.98:1 orgreater; more preferably 0.99:1 or greater; more preferably 0.995:1 orgreater. Preferably, the mole ratio of —Y groups to —X— groups is1.001:1 or lower.

The polymer in the resin bead of the present invention may be any typeof polymer, including, for example, step-reaction polymers and vinylpolymers. Step-reaction polymers include, for example, polyesters,polyamides, polyurethanes, celluloses, phenol-aldehydes, urea aldehydes,polysulfides, and polysiloxanes. Vinyl polymers include polymers havingpolymerized units of acrylic monomers or olefin monomers or styrenicmonomers or mixtures thereof. Preferred are vinyl polymers; morepreferred are vinyl polymers containing polymerized units of styrenicmonomers or acrylic monomers or mixtures thereof; more preferred arevinyl polymers containing polymerized units of styrenic monomers. Amongvinyl polymers, preferred are those in which the amount of polymerizedunits of styrenic monomers is, by weight based on the weight of thevinyl polymer, 50% or more; more preferably 75% or more; more preferably90% or more; more preferably 95% or more.

Preferably the amount of pendant groups that contain both one or moresulfur atoms and one or more oxygen atoms is, by weight based on theweight of polymer, 0 to 0.01%; more preferably 0 to 0.003%; morepreferably 0 to 0.001%; more preferably 0%. Preferably the amount ofpendant groups that contain one or more sulfur atoms is, by weight basedon the weight of polymer, 0 to 0.01%; more preferably 0 to 0.003%; morepreferably 0 to 0.001%; more preferably 0%. Preferably the amount ofpendant groups that contain both one or more carboxyl groups, either inhydrogenated form or in anionic form, is, by weight based on the weightof polymer, 0 to 0.01%; more preferably 0 to 0.003%; more preferably 0to 0.001%; more preferably 0%. Preferably the amount of pendant groupsother than —X— and —Y as defined above is, by weight based on the weightof polymer, 0 to 0.01%; more preferably 0 to 0.003%; more preferably 0to 0.001%; more preferably 0%.

Preferably the resin beads contain polymer in an amount, by weight basedon the weight of the resin beads, of 50% or more; more preferably 60% ormore; more preferably 70% or more; more preferably 80% or more; morepreferably 90% or more; more preferably 95% or more; more preferably 98%or more.

The resin beads of the present invention preferably are in a collectionof beads that has harmonic mean particle diameter of 100 μm or higher;more preferably 200 μm or higher; more preferably 300 μm or higher; morepreferably 400 μm or higher; more preferably 500 μm or higher. The resinbeads of the present invention preferably are in a collection of beadsthat has harmonic mean particle diameter of 2000 μm or lower; morepreferably 1000 μm or lower.

The resin beads of the present invention preferably are in a collectionof beads that has uniformity coefficient of 1.02 or higher; morepreferably 1.09 or higher; more preferably 1.16 or higher; morepreferably 1.2 or higher; more preferably 1.3 or higher. The resin beadsof the present invention preferably are in a collection of beads thathas uniformity coefficient of 2 or lower; more preferably 1.8 or lower.

The resin beads of the present invention are preferably macroporous.

The resin beads of the present invention may be made by any method. In apreferred method, a resin is supplied having pendant groups, where thependant group has a subgroup in which two carbon atoms are bonded toeach other, and each of those two carbon atoms is also bonded to ahydroxyl group, and the subgroup is in the cis-diol configuration. Theresin is then preferably put into contact with H₃BO₃, and the subgroupreacts with H₃BO₃ to form a preferred —Y group.

The second aspect of the present invention is the processing of anaqueous solution. In the practice of the second aspect of the presentinvention, the resin bead may or may not contain multivalent atomiccations, and if multivalent atomic cations are present, the mole ratioof multivalent atomic cations to —X— groups may or may not be 0.01:1 orlower. However, it is preferable that the amount of multivalent atomiccation is the same as the preferable amounts described above for thefirst aspect of the present invention.

All of the resin characteristics, including the Y replacement impuritylevels, that are described above as suitable for the first aspect of thepresent invention are also suitable for the resin beads used in thesecond aspect of the present invention.

Preferably, the aqueous solution contains one or more sugars that aredissolved in the aqueous solution. Preferably, the aqueous solutioncontains sucrose. Preferably, the aqueous solution contains glucose.Preferably, the weight ratio of fructose to glucose is 0.1:1 or greater;more preferably 0.2:1 or greater; more preferably 0.5:1 or greater.Preferably, the weight ratio of fructose to glucose is 10:1 or lower;more preferably 5:1 or lower; more preferably 2:1 or lower.

Preferably, the aqueous solution contains one or more sugars selectedfrom mannose, arabinose, maltose, sucrose, galactose, raffinose,stachyose, lactose, xylose, trehalose, isomaltulose, isomers thereof,versions thereof with various hydrate levels, and mixtures thereof; morepreferably maltose, sucrose, raffinose, stachyose, lactose, trehalose,isomaltulose, isomers thereof, versions thereof with various hydratelevels, and mixtures thereof; more preferably maltose, sucrose,D-raffinose, stachyose, D lactose, trehalose, isomaltulose, and mixturesthereof.

Preferably, the aqueous solution contains one or more sugar alcoholsthat are dissolved in the aqueous solution. Preferred sugar alcohols areinositol, xylitol, maltitol, meso-erythritol, D-mannitol, sorbitol,isomers thereof, and mixtures thereof; more preferred are inositol,xylitol, D-mannitol, sorbitol, and mixtures thereof.

Preferably, the total amount of all sugars in the aqueous solution is,by weight based on the weight of the aqueous solution, 0.1% or more;more preferably 0.5% or more; more preferably 1% or more; morepreferably 5% or more; more preferably 10% or more. Preferably, thetotal amount of all sugars in the aqueous solution is, by weight basedon the weight of the aqueous solution, 70% or less; more preferably 60%or less.

Preferably, the aqueous solution has pH of less than 6; more preferably5.5 or less; more preferably 5 or less; more preferably 4.5 or less.Preferably, the aqueous solution has pH of 2 or more; more preferably2.5 or more.

Preferably, the total amount of all sugar alcohols in the aqueoussolution is, by weight based on the weight of the aqueous solution,0.05% or more; more preferably 0.1% or more. Preferably, the totalamount of all sugar alcohols in the aqueous solution is, by weight basedon the weight of the aqueous solution, 15% or less; more preferably 10%or less.

In some embodiments, the aqueous solution contains ethanol.

In some embodiments, the aqueous solution contains one or more dissolvedinorganic salt. Among dissolved inorganic salts, preferred cations aresodium, potassium, and mixtures thereof; more preferably potassium.Among dissolved inorganic salts, the preferred anion is chloride.Preferably, the total amount of all dissolved inorganic salts is, byweight based on the weight of the aqueous solution, 0-10%; morepreferably 0-5%.

It is contemplated that contacting the aqueous solution with the resinbeads will be performed as part of a process that serves to separatessome of the dissolved components from each other. Any such process ofseparating the components is contemplated. Two examples of suchprocesses are pulse processes and continuous processes.

In a pulse process a fixed amount of resin beads and a fixed amount ofaqueous solution are brought into contact. For example, the resin beadsmay be present in a container that has an inlet that allows liquid intothe container and an outlet that allows liquid to exit the container,while retaining the resin beads in the container. An example of such acontainer is a chromatography column. For example, in a pulse processthat employs a chromatography column, a fixed amount of resin beadscould be placed in the column, and then a fixed amount of the aqueoussolution could be placed at the top of the column in contact with theresin beads. Then, a liquid called an “eluent” could be passed throughthe inlet onto the top of the column, travel through the column, makingcontact with the resin beads, and exit through the outlet. A sufficientvolume of eluent could be passed through the column until all of thedesired components were removed. It is contemplated that differentcomponents will proceed through the column and out through the outlet,dissolved in the eluent, at different speeds because of differentaffinities for the resin beads.

In a pulse process, preferred eluents are aqueous solutions that, priorto entry into the column, do not contain any sugars or sugar alcohols.Preferred eluents are aqueous solutions of pH 3 to 11 that optionallycontain one or more dissolved inorganic salts; more preferred is waterof pH 3 to 11 that does not contain significant amounts of any solutesother than those necessary to establish the desired pH. The mostpreferred eluent is water of pH 6 to 8.

In a continuous process, fresh aqueous solution is continuously broughtinto contact with resin beads, and one or more product stream is removedfrom the resin beads. A preferred continuous process is a simulatedmoving bed (SMB) process. SMB processes are explained, for example, byJuza et al. in Trends in Biotechnology (TIBTECH) volume 18, March 2000,pp 108-118, and by Rajendran et al. in Journal of Chromatography A,volume 1216, 2009, pp 709-738. The eluents (also called “desorbents” inSMB processes) preferred for use in an SMB process are the same as thosediscussed above for a pulse process.

In some embodiments, a pulse process is performed as a test in order todetermine the feasibility of a continuous process. For example, anaqueous solution of compound “A” may be processed in a pulse processusing water as eluent, and the retention time (that is, the time neededfor “A” to leave the column) is noted. Then, a separate pulse processmay be performed on an aqueous solution of compound “B” also using wateras an eluent, under the same conditions, and the retention time of “B”is noted. If the retention times for “A” and “B” are sufficientlydifferent, it is contemplated that a solution that contained both “A”and “B” could be separated into separate solutions, one containing “A”and the other containing “B,” by using an SMB process.

To determine if the retention times for “A” and “B” are sufficientlydifferent, the resolution is studied. Resolution is defined, forexample, by Fornstedt, et al. in Chapter 1 of Analytical SeparationSciences, (Anderson, et al., editors), published by Wiley-VCH, 2015). Inthe pulse process for “A,” the concentration of “A” in the exit streamfrom the column is studied as a function of time, with time equal tozero at the moment the eluent flow is begun. The concentration versustime forms a peak, which is modeled as a triangle. The time value at theapex of the triangle is the retention time (t_(A)), and the peak width(W_(A)) is the width of the triangle at the baseline. The pulse processfor “B” determines the retention time (t_(B)), and the peak width(W_(B)) characteristic of “B”. When “B” is the compound with higherretention time, the resolution R_(AB) is then

R _(AB)=2(t _(B) −t _(A))/(W _(A) +W _(B))

Higher resolution means that the pair of “A” and “B” could be morereadily separated.

The following are examples of the present invention.

EXAMPLE 1: PREPARATION OF RESIN BEADS

Resin beads DOWEX™ BSR-1 were used. These beads are macroporous, containstyrene/divinylbenzene copolymer, and contain pendant groups of thestructure (S18):

where the symbol

represents the polymer backbone. The two carbon atoms at the far righthand side of (S18) and their attached hydroxyl groups are in a cis-diolconfiguration. To make the resin beads of the present invention, 1.5 Lof DOWEX™ BSR-1 beads was mixed with 2 L of a 2.0 N solution of H₃BO₃ indeionized water. The mixture was stirred for 2 hours at room temperature(approximately 23° C.). Then excess liquid was decanted, and the resinwas rinsed with deionized water until the pH of the rinse water wasapproximately 7. It is contemplated that the pendant groups shown abovewere all converted to the following structure (S19):

The collection of resin beads produced in Example 1 had harmonic meandiameter of 611 μm and had uniformity coefficient of 1.39.

EXAMPLE 2: PULSE TESTS ON VARIOUS SOLUTES

Pulse tests were performed on the following solutes:

TABLE 1 List of Solutes Label Solute A Inositol B Xylitol C D-Mannose DGlucose E Maltitol F L-Arabinose G Maltose H Sucrose I Meso-Erythritol JD-Galactose K D-Raffinose (Pentahydrate) L Stachyose M D-Mannitol ND-Lactose (Monohydrate) O D-Xylose P Sorbitol Q Fructose S PotassiumChloride T Trehalose U Isomaltulose

Pulse tests were performed as follows. A solution of a single solute wasprepared at 20% by weight solute in water. A column was used that was 91cm tall and 2.7 cm diameter. Volume of resin packed in the column was526 mL. 26.3 mL of the solution was placed on top of the resin in thecolumn. Elution was performed with water at 2.0 column volumes per hour(17.47 mL/min) at 60° C. “Comparative” (“Com”) tests were performedusing DOWEX™ BSR-1 resin, and “Example” (“Ex”) tests were performedusing resin made by the method of Example 1.

For each pulse test, a retention time and a width was determined. Then,for a given resin type and a given pair of solutes, a resolution wasdetermined using resolution calculation as defined by Fornstedt et al.,as described above. The resolution values were as follows: [112]

TABLE 2A Resolution Values for Solute Pairs A A B B C C D D Com Ex ComEx Com Ex Com Ex B 0.032 0.260 C 0.040 0.064 0.009 0.200 D 0.008 0.0230.023 0.274 0.032 0.085 E 0.044 0.061 0.074 0.187 0.081 0.002 0.0510.081 F 0.063 0.098 0.031 0.170 0.022 0.034 0.054 0.118 G 0.035 0.0270.065 0.277 0.073 0.089 0.042 0.004 H 0.043 0.025 0.074 0.268 0.0810.085 0.051 0.003 I 0.058 0.087 0.026 0.174 0.017 0.025 0.050 0.107 J0.027 0.068 0.004 0.184 0.012 0.008 0.019 0.088 K 0.077 0.065 0.1070.283 0.114 0.118 0.084 0.044 L 0.149 0.087 0.181 0.345 0.188 0.1510.157 0.060

As an illustration of how data are presented in the table above, thefollowing is noted. For solutes J and B, resolution in the comparativeresin was 0.004, while resolution in the Example resin was 0.184.

TABLE 2B Resolution Values for Solute Pairs E E F F G G H H Com Ex ComEx Com Ex Com Ex F 0.104 0.030 G 0.008 0.084 0.095 0.122 H 0.001 0.0810.104 0.117 0.008 0.001 I 0.100 0.022 0.005 0.008 0.091 0.111 0.1000.107 J 0.069 0.006 0.034 0.024 0.060 0.092 0.069 0.088 K 0.033 0.1130.136 0.148 0.041 0.040 0.034 0.040 L 0.098 0.142 0.214 0.188 0.1070.055 0.100 0.055

TABLE 2C Resolution Values for Solute Pairs I I J J K K Com Ex Com ExCom Ex J 0.029 0.016 K 0.133 0.137 0.101 0.120 L 0.211 0.174 0.173 0.1520.061 0.006

TABLE 2D Resolution Values for Solute Pairs E E F F G G H H Com Ex ComEx Com Ex Com Ex F 0.104 0.030 G 0.008 0.084 0.095 0.122 H 0.001 0.0810.104 0.117 0.008 0.001 I 0.100 0.022 0.005 0.008 0.091 0.111 0.1000.107 J 0.069 0.006 0.034 0.024 0.060 0.092 0.069 0.088 K 0.033 0.1130.136 0.148 0.041 0.040 0.034 0.040 L 0.098 0.142 0.214 0.188 0.1070.055 0.100 0.055

TABLE 2E Resolution Values for Solute Pairs A A B B C C D D Com Ex ComEx Com Ex Com Ex M 0.021 0.224 0.010 0.025 0.018 0.167 0.013 0.239 N0.051 0.040 0.081 0.293 0.089 0.103 0.059 0.016 O 0.080 0.189 0.0490.060 0.040 0.131 0.071 0.205 P 0.016 0.334 0.015 0.096 0.023 0.2800.008 0.345 Q 0.040 0.285 0.009 0.026 0.000 0.225 0.032 0.298 S 0.0150.133 0.022 0.160 0.031 0.062 0.006 0.154 T 0.035 0.032 0.065 0.2840.073 0.094 0.043 0.008 U 0.046 0.352 0.076 0.146 0.083 0.307 0.0530.361

TABLE 2F Resolution Values for Solute Pairs E E F F G G H H Com Ex ComEx Com Ex Com Ex M 0.063 0.156 0.040 0.138 0.055 0.242 0.063 0.235 N0.008 0.097 0.111 0.137 0.016 0.012 0.009 0.013 O 0.119 0.122 0.0190.102 0.111 0.208 0.120 0.201 P 0.058 0.264 0.045 0.255 0.049 0.3470.058 0.338 Q 0.081 0.211 0.021 0.197 0.072 0.301 0.081 0.292 S 0.0650.056 0.058 0.026 0.055 0.158 0.065 0.151 T 0.008 0.089 0.095 0.1280.000 0.004 0.007 0.005 U 0.002 0.292 0.106 0.285 0.010 0.363 0.0020.355

TABLE 2G Resolution Values for Solute Pairs I I J J K K L L Com Ex ComEx Com Ex Com Ex M 0.035 0.142 0.006 0.153 0.096 0.252 0.168 0.306 N0.107 0.125 0.076 0.106 0.025 0.030 0.089 0.044 O 0.024 0.107 0.0510.118 0.151 0.221 0.228 0.271 P 0.041 0.256 0.011 0.263 0.091 0.3460.162 0.410 Q 0.016 0.199 0.012 0.209 0.112 0.304 0.185 0.369 S 0.0520.034 0.017 0.050 0.104 0.181 0.192 0.232 T 0.091 0.116 0.060 0.0970.041 0.037 0.106 0.052 U 0.102 0.286 0.071 0.361 0.032 0.361 0.0970.417

TABLE 2H Resolution Values for Solute Pairs M M N N O O P P Com Ex ComEx Com Ex Com Ex N 0.071 0.257 O 0.057 0.034 0.127 0.223 P 0.005 0.1160.066 0.363 0.063 0.149 Q 0.018 0.050 0.088 0.317 0.039 0.086 0.0230.071 S 0.010 0.126 0.074 0.175 0.078 0.087 0.004 0.251 T 0.055 0.2480.016 0.008 0.111 0.214 0.050 0.354 U 0.065 0.163 0.006 0.377 0.1220.191 0.060 0.058

TABLE 2I Resolution Values for Solute Pairs Q Q S S T T Com Ex Com ExCom Ex S 0.031 0.189 T 0.072 0.308 0.055 0.165 U 0.083 0.124 0.068 0.2840.010 3.465

Use of the Example resin brings about a general improvement in theresolution values. For example, for a specific pair of solutes, one canconsider the quotient of the resolution values RQ=(resolution using Exresin)/(resolution using Com resin).

One aspect of the general improvement becomes apparent if the resultsare ignored for pairs where the resolution is low for both the Com resinand the Ex resin. For example, in one analysis, the data are ignored if,for a specific pair of solutes, the resolution using Com resin and theresolution using Ex resin are both below 0.16. In this analysis, bothresins are poor at resolution for that specific pair of solutes, and soit is irrelevant which one is better. In the remaining data (that is,when all the solute pairs are considered in which one resolution or theother, or both, is 0.16 or above, the quotient RQ varies from 0.81(solute pair CL) to 659 (solute pair CQ). Thus, whenever at least oneresin has a resolution of 0.16 or higher, either the resins are similaror else the Example resin is better, possibly far better.

In another analysis, pairs are considered in which results are ignoredfor solute pairs in which the resolution using the Comparative resin andthe resolution using the Example resin are both below 0.22. Then thequotient RQ varies from 1.19 (solute pair LO) to 659 (solute pair CQ).Thus, in any solute pair in which at least one resin shows relativelygood resolution (that is, 0.22 or above), the Example resin is alwaysbetter. A few representative RQ values from this data set are shownbelow:

Solute Pair: AM AP BC BD BJ CP CQ DM DP RQ: 10 21 23 12 52 12 659 18 43Solute Pair: EU HU IQ JP JQ KU NU PS TU RQ: 179 143 12 24 17 11 62 70361

EXAMPLE 3: SEPARATION OF MIXED-SUGAR SOLUTION

The following Comparative Resins were tested:

CR-2=Macroporous resin similar to the resin of Example 1, having thesame harmonic mean diameter (611 ft m) and the same uniformitycoefficient (1.39). However, the pendant groups, instead of (S19), were(S20):

CR-3=Macroporous resin similar to CR-2, but harmonic mean diameter of640 μm and uniformity coefficient of less than 1.1.

CR-4=Resin similar to CR-2, but was a gel resin, had harmonic meandiameter of 320 μm and had uniformity coefficient of less than 1.1.

CR-5=DOWEX™ BSR-1. This resin is similar to Example 1 except for havingpendant groups (S18) instead of pendant groups (S19).

An aqueous sugar solution was prepared that contained 42% by weightfructose, that also contained glucose, and that had 50.05% dissolvedsolids by weight. Sugar concentration was 50 Brix.

Resin was placed in a column as in Example 2. A sample of the aqueoussugar solution was placed onto the top of the column. The volume ofaqueous sugar solution was 11.2% of the column volume. The column wasthen eluted with water at 1.2 bed volume per hour at 60° C. The columnhad 25 mm diameter and 1219 mm length. Total bed volume was 525 mL.Individual fractions of eluate were collected with an autosampler. Eachfraction was analyzed for the presence and type of sugar using highperformance liquid chromatography (HPLC) using AMINEX™HPX-87C column(Bio-Rad Laboratories, Inc.) at 85° C., 0.6 mL/min, 20 μL injectionvolume. The concentration results for glucose and fructose from thefractions were plotted against the elution volume (bed volumes) and theresolution calculated using the methods described above. As in Example2, a resolution value for glucose and fructose was obtained. Theexperiment was performed four times, using four different resins, withresults as follows:

Resin Size⁽¹⁾ UC⁽²⁾ Pendant Type⁽³⁾ Resolution Example 1 611 μm 1.39 S19M 0.37 CR-2 611 μm 1.39 S20 M 0.16 CR-3 640 μm <1.1 S20 M 0.19 CR-4 320μm <1.1 S20 gel 0.32 CR-5 611 μm 1.39 S18 M 0.01 ⁽¹⁾Harmonic MeanDiameter ⁽²⁾Uniformity Coefficient ⁽³⁾M = macroporous

The table shows that, when using sulfonate pendant groups (i.e., S20),the only resin having resolution value above 0.3 was CR-4, which hadboth small diameter and uniform distribution. The Example 1 resin (usingthe Boron-containing pendant group S19) achieved the best resolutionvalue even though it has relatively large size and relatively largeuniformity coefficient. Also, comparison of Example 1 with CR-5 showsthat the presence of the boron-containing group greatly improves theresolution.

1. A resin bead comprising functional groups of structure (S1)

wherein —X— is a bivalent linking group, wherein —Y is a monovalentgroup having structure (S2)

wherein the circular structure in structure (S2) has four or more atoms,wherein the mole ratio of multivalent atomiccations to —X— groups iseither 0:1 or is 0.01:1 or lower.
 2. The resin bead of claim 1, wherein—Y is selected from the group consisting of structures (S3), (S4), and(S5):

wherein each of -A¹-, -A²-, -A³-, -A⁴-, and -A⁵- is independentlyselected from the group consisting of structure (S6), (S7), and (S8):

wherein each of R¹, R², and R³ is independently selected from the groupconsisting of hydrogen, hydroxyl, amine, unsubstituted alkyl, andsubstituted alkyl.
 3. The resin bead of claim 1, wherein —X— comprisesone or more structure (S7), one or more structure (S8), one or morestructure (S9), or a combination thereof, wherein structure (S7),structure (S8), and structure (S9) are defined as follows:

wherein the aromatic ring in structure (S9) may be substituted orun-substituted, and wherein each of R¹ and R² is independently selectedfrom the group consisting of hydrogen, hydroxyl, amine, unsubstitutedalkyl, and substituted alkyl, and wherein R³ is selected from the groupconsisting of hydrogen, unsubstituted alkyl, and substituted alkyl. 4.The resin bead of claim 1, wherein the mole ratio of —Y groups to —X—groups is 0.99:1 or higher.
 5. A collection of the resin beads of claim1, wherein the collection has harmonic mean diameter of 200 μm orhigher.
 6. The collection of resin beads of claim 5, wherein thecollection has uniformity coefficient of 1.02 or greater.